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Channels (Austin). 2016;10(1):45-54. doi: 10.1080/19336950.2015.1075677. Epub 2015 Jul 28.

Calmodulin and Ca(2+) control of voltage gated Na(+) channels.

Author information

1
a Structural Enzymology and Thermodynamics Group; Department of Biophysics and Biophysical Chemistry , Johns Hopkins University School of Medicine , Baltimore , MD USA.
2
b Division of Cardiology; Department of Medicine, Johns Hopkins University School of Medicine ; Baltimore , MD USA.
3
c Department of Oncology ; Johns Hopkins University School of Medicine ; Baltimore , MD USA.

Abstract

The structures of the cytosolic portion of voltage activated sodium channels (CTNav) in complexes with calmodulin and other effectors in the presence and the absence of calcium provide information about the mechanisms by which these effectors regulate channel activity. The most studied of these complexes, those of Nav1.2 and Nav1.5, show details of the conformations and the specific contacts that are involved in channel regulation. Another voltage activated sodium channel, Nav1.4, shows significant calcium dependent inactivation, while its homolog Nav1.5 does not. The available structures shed light on the possible localization of the elements responsible for this effect. Mutations in the genes of these 3 Nav channels are associated with several disease conditions: Nav1.2, neurological conditions; Nav1.4, syndromes involving skeletal muscle; and Nav1.5, cardiac arrhythmias. Many of these disease-specific mutations are located at the interfaces involving CTNav and its effectors.

KEYWORDS:

Nav; SCN2A; SCN4A; SCN5A; calcium inactivation; calmodulin; voltage gated sodium channels

PMID:
26218606
PMCID:
PMC4802738
DOI:
10.1080/19336950.2015.1075677
[Indexed for MEDLINE]
Free PMC Article

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